5,302 research outputs found

    Why vocal production of atypical sounds in apes and its cerebral correlates have a lot to say about the origin of language

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    Ackermann et al. mentioned the "acquisition of species-atypical sounds" in apes without any discussions. In our commentary, we demonstrate that these atypical sounds in chimpanzees not only include laryngeal sounds but also have a major significance regarding the origins of language, if we consider looking at their context of use, their social properties, their relations with gestures, their lateralization and their neurofunctional correlates as well

    Lee Porter (1947-1989)

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    Lee Porter died unexpectedly in Seattle, Washington, on 18 January 1989. ... [After initially training in journalism] Lee became a specialist in the Pleistocene biostratigraphy of arctic regions, particularly Alaska and the U.S.S.R. ... Lee's subsequent career took her to the British Museum of Natural History on a research fellowship, then to teaching and administration at Northern Arizona University. She also worked as a consultant for several engineering firms, applying her knowledge of Quaternary deposits to environmental problems, such as geologic hazards, site stability, and waste disposal. At the time of her death, she was working as an engineering geologist for the California State Department of Transportation. ..

    Geotechnical, Hydrologic, and Hydraulic Investigation of Mill Creek Dam-Phase II

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    The general scope of this study, Phase II, was to assess the safety of Mill Creek Dam. Findings obtained from detailed geotechnical, hydraulic, and hydrological investigations are presented. The structural stability, as well as the hydrological and hydraulic stability, were investigated. Specifically, objectives of the study were as follows: 1. To determine the engineering characteristics of the clay core, shells, and random fill. 2. To evaluate the potential for piping. 3. To evaluate seepage conditions at the site. 4. To evaluate the structural stability of the earth and rockfill dam. 5. To evaluate erodability. 6. To assess geologic conditions at the site. 7. To evaluate existing and required spillway hydraulics and hydrology of the site. 8. To analyze requirements for a drawdown facility. 9. To evaluate alternative remedial measures that could be used to correct deficiencies in the dam. This study presents data relating to the degree of safety and alternative remedial schemes. Information presented herein will aid in the final selection of the remedial method and in implementing remedial construction. Development of detailed remedial plans, however, was not within the scope of this study

    The Largest Known Maars on Earth, Seward Peninsula, Northwest Alaska

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    The Espenberg Maars on the northern Seward Peninsula of Alaska were formed by a series of Pleistocene basaltic eruptions through thick permafrost. The maars were excavated as much as 300 m into older lithologies; ranging from 4 to 8 km in diameter, they are the four largest known maars on earth. Hydromagmatic eruptions which derive water from ground ice are evidently extremely explosive. The high heat capacity of ice in permafrost modulates the supply of water interacting with magma during the eruption, producing consistently low coolant-to-fuel ratios in an environment with a sustained, abundant water supply. The Espenberg Maars demonstrate that, under certain conditions, eruptions which involve the interaction of lava and permafrost are powerful enough to produce craters as large as small calderas.Les maars de l'Espenberg situés dans la partie septentrionale de la péninsule Seward en Alaska ont été formés par une série d'éruptions basaltiques datant du pléistocène, à travers une forte épaisseur de pergélisol. Les maars ont été creusés à une profondeur allant jusqu'à 300 m dans d'anciennes roches; d'un diamètre variant entre 4 et 8 km, ils sont les quatre plus grands maars connus sur Terre. Les éruptions hydromagmatiques qui tirent l'eau de la glace de sol sont, comme on l'a déjà constaté, extrêmement explosives. La grande capacité thermique de la glace dans le pergélisol détermine l'approvisionnement en eau qui interagit avec le magma au cours de l'éruption, donnant régulièrement lieu à un faible rapport refroidissant / combustible dans un environnement où l'eau est constamment abondante. Les maars de l'Espenberg démontrent que, dans certaines conditions, les éruptions qui déclenchent une interaction lave-pergélisol sont suffisamment puissantes pour donner naissance à des cratères de la grandeur de petites calderas

    The BASES expert statement on the effects of exercise on appetite control and energy intake

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    Apes communicate about absent and displaced objects: methodology matters

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    Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences

    Review of Pertinent Contract Documents Tennessee-Tombigbee Waterway Divide Cut Section 3A

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    During construction of a portion of the Tombigbee Canal near Corinth, Mississippi, southward from Pickwick Lake (Station 13,118+00 to 13,337+50), the Contractor reported various problems, which he termed differing site conditions. Some of the items considered as problems by the Contractor were: the amount of cherty Paleozoic material was far less than he expected or anticipated, there were deep deposits of bluish muck, the alluvial was not sufficiently stable to place in 1-foot lifts, excessively wet materials made it necessary to shift equipment frequently, the equipment had to travel over bad roads, and the materials had no bearing strength

    Knee joint neuromuscular activation performance during muscle damage and superimposed fatigue

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    This study examined the concurrent effects of exercise-induced muscle damage and superimposed acute fatigue on the neuromuscular activation performance of the knee flexors of nine males (age: 26.7 ± 6.1yrs; height 1.81 ± 0.05m; body mass 81.2 ± 11.7kg [mean ± SD]). Measures were obtained during three experimental conditions: (i) FAT-EEVID, involving acute fatiguing exercise performed on each assessment occasion plus a single episode of eccentric exercise performed on the first occasion and after the fatigue trial; (ii) FAT, involving the fatiguing exercise only and; (iii) CON consisting of no exercise. Assessments were performed prior to (pre) and at lh, 24h, 48h, 72h, and 168h relative to the eccentric exercise. Repeated-measures ANOVAs showed that muscle damage within the FAT-EEVID condition elicited reductions of up to 38%, 24%) and 65%> in volitional peak force, electromechanical delay and rate of force development compared to baseline and controls, respectively (F[io, 80] = 2.3 to 4.6; p to 30.7%>) following acute fatigue (Fp; i6] = 4.3 to 9.1; p ; Fp, iq = 3.9; p <0.05). The safeguarding of evoked muscle activation capability despite compromised volitional performance might reveal aspects of capabilities for emergency and protective responses during episodes of fatigue and antecedent muscle damaging exercise

    Effects of D-amino acid oxidase inhibition on memory performance and long-term potentiation in vivo

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    N-methyl-d-aspartate receptor (NMDAR) activation can initiate changes in synaptic strength, evident as long-term potentiation (LTP), and is a key molecular correlate of memory formation. Inhibition of d-amino acid oxidase (DAAO) may increase NMDAR activity by regulating d-serine concentrations, but which neuronal and behavioral effects are influenced by DAAO inhibition remain elusive. In anesthetized rats, extracellular field excitatory postsynaptic potentials (fEPSPs) were recorded before and after a theta frequency burst stimulation (TBS) of the Schaffer collateral pathway of the CA1 region in the hippocampus. Memory performance was assessed after training with tests of contextual fear conditioning (FC, mice) and novel object recognition (NOR, rats). Oral administration of 3, 10, and 30 mg/kg 4H-furo[3,2-b]pyrrole-5-carboxylic acid (SUN) produced dose-related and steady increases of cerebellum d-serine in rats and mice, indicative of lasting inhibition of central DAAO. SUN administered 2 h prior to training improved contextual fear conditioning in mice and novel object recognition memory in rats when tested 24 h after training. In anesthetized rats, LTP was established proportional to the number of TBS trains. d-cycloserine (DCS) was used to identify a submaximal level of LTP (5× TBS) that responded to NMDA receptor activation; SUN administered at 10 mg/kg 3–4 h prior to testing similarly increased in vivo LTP levels compared to vehicle control animals. Interestingly, in vivo administration of DCS also increased brain d-serine concentrations. These results indicate that DAAO inhibition increased NMDAR-related synaptic plasticity during phases of post training memory consolidation to improve memory performance in hippocampal-dependent behavioral tests
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